The present invention relates to method of detecting leakage in a hydraulic circuit.
A conventional hydraulic circuit such as found on an off-road vehicle to operate control cylinders associated with a vehicle component, for example, a loader bucket, boom, etc., includes in essential part, a pump driven by the vehicle's engine, a sump, and a control valve responsible for selectively porting hydraulic fluid to the various cylinders. The hydraulic circuit inclusive of the cylinders will contain a plurality of O-rings, seals, check valves and other constituent components which are subject to develop leakage. The presence of excessive leakage results in heat build up further degrading the component. Further, leakage precipitates a drop in circuit pressure requiring an increased power input to the circuit to compensate for the drop in pressure and, thereby, increases the fuel consumption rate of the engine.
One conventional method of detecting leakage within a hydraulic circuit involves interrupting the circuit at various points, each point relating to a particular circuit branch identified with a particular cylinder and introducing a flow meter to the circuit. The engine is started with all components in neutral. Should the flow meter register, a flow leakage is is indicated.
Another conventional method of detecting circuit leaks involves interrupting the circuit at various points, each relating to a particular circuit branch identified with a particular cylinder and introducing a pressure gage. The particular cylinder relating to a particular branch, previously set in a maximum or minimum position, is further urged to the maximum or minimum position, respectively, i.e., max to max or minimum to minimum. Should the pressure gage indicate a drop in circuit pressure, a leak is indicated.
Each of the conventional methods utilize relatively costly instrumentation. Further, the methods are time consuming and by interrupting the circuit create a further potential for leakage and the instrumentation is removed at the interruption point when the circuit is mended. Another disadvantage of the conventional methods is their inability to detect leaks of relatively small magnitudes.